RME ADI-2 DAC Thread
May 8, 2019 at 4:08 PM Post #1,262 of 4,643

CaptainFantastic

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Quick question: if using an amp with the ADI-2 (line out RCA), and Auto Ref Level is set to "OFF", what is the best Ref Level and why? Mine defaulted to +1 dBu and VOL is at -12.5 dB. Are these the default settings for a reason or are they not even the default and I changed them without noticing?
 
May 8, 2019 at 7:04 PM Post #1,264 of 4,643

Dogmatrix

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Quick question: if using an amp with the ADI-2 (line out RCA), and Auto Ref Level is set to "OFF", what is the best Ref Level and why? Mine defaulted to +1 dBu and VOL is at -12.5 dB. Are these the default settings for a reason or are they not even the default and I changed them without noticing?
All depends on what input voltage your amp can handle . I run my Violectric at +19 balanced because it is rated for pro line level . Generally you want to run as high as possible to give the best s/n ratio
 
May 8, 2019 at 7:04 PM Post #1,265 of 4,643

Anaz

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Quick question: if using an amp with the ADI-2 (line out RCA), and Auto Ref Level is set to "OFF", what is the best Ref Level and why? Mine defaulted to +1 dBu and VOL is at -12.5 dB. Are these the default settings for a reason or are they not even the default and I changed them without noticing?

Per section 19.3 of the ADI-2 User's Guide, the effective SNR at the output is max SNR dB minus the value of the volume pot dB -- e.g. in your case, SNR = 114 dB - 12.5 dB = 101.5 dB. ...Which is still a good SNR and the drop from the theoretical max of 117 dB on XLR may not even be audible in normal listening.

Personally, I set the ADI-2's volume to 0 dB* and use a Line Out dB setting that gives me good travel on my amp's volume pot.

Don't know about default, but as long as you are not clipping. I use mine with the Auto Ref ON and -5db. If using EQ or other things, you might clip.

* Good advice. When using EQ I set the ADI-2's volume to -0.5 dB or -1 dB.

Edit: fixed SNR values
 
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May 8, 2019 at 7:21 PM Post #1,266 of 4,643

Anaz

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All depends on what input voltage your amp can handle . I run my Violectric at +19 balanced because it is rated for pro line level . Generally you want to run as high as possible to give the best s/n ratio

I've heard that too. Do you use pre gain on your Violectric and if so what setting?
 
May 8, 2019 at 8:04 PM Post #1,267 of 4,643

Dogmatrix

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I've heard that too. Do you use pre gain on your Violectric and if so what setting?
Yes pre gain is -6 just to move my preferred volume level to 12 0'clock , on zero only 1/4 range is useable . That is running my HE500 other phones vary slightly .
For reference a domestic line level of 2volts rms is +9 dbu , on my pro that is +13 dbu level and -4 dbu volume . I run my tube amps at that level .
 
May 8, 2019 at 9:25 PM Post #1,268 of 4,643

Anaz

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Yes pre gain is -6 just to move my preferred volume level to 12 0'clock , on zero only 1/4 range is useable . That is running my HE500 other phones vary slightly .
For reference a domestic line level of 2volts rms is +9 dbu , on my pro that is +13 dbu level and -4 dbu volume . I run my tube amps at that level .

Very informative. ...I'm outputting +13 dB XLR to a V281 with a pre gain of -12 dB and I generally have the V281's volume pot between 8:00 to 10:00 depending on headphone (typically Focals using balanced cable) and music.
 
May 10, 2019 at 12:31 PM Post #1,269 of 4,643

Relaxasaurus

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Very informative. ...I'm outputting +13 dB XLR to a V281 with a pre gain of -12 dB and I generally have the V281's volume pot between 8:00 to 10:00 depending on headphone (typically Focals using balanced cable) and music.
I tried setting my v280 at -12 dB input gain and started upping the output volume and the ADI-2 but I was getting clipping due to my EQ settings so I'm back to -12 on the ADI and 0 dB gain on the amp.
 
May 10, 2019 at 1:38 PM Post #1,270 of 4,643

Anaz

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I tried setting my v280 at -12 dB input gain and started upping the output volume and the ADI-2 but I was getting clipping due to my EQ settings so I'm back to -12 on the ADI and 0 dB gain on the amp.

What’s your Line Out : Ref Level setting? e.g. my ADI-2’s Ref Level is +7 dB (actual XLR output is 6 dB higher than the value of the setting) and volume is at 0 dB
 
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May 11, 2019 at 12:42 AM Post #1,271 of 4,643

Litlgi74

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I'm glad to see there are a few users on this form using the RME ADI-2 DAC along with the Violectric V281...

I too am considering the V281 to complement the RME... But didn't seem any reviews or opinions.

Hoping someone might be willing to give the pros and cons of this combo... I should have a new pair of Abyss AB-1266 next week... andan don't think the ADI-2 DAC on its own can power such headphones.

Thanks
 
May 11, 2019 at 3:09 PM Post #1,272 of 4,643

Anaz

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I'm glad to see there are a few users on this form using the RME ADI-2 DAC along with the Violectric V281...

I too am considering the V281 to complement the RME... But didn't seem any reviews or opinions.

Hoping someone might be willing to give the pros and cons of this combo... I should have a new pair of Abyss AB-1266 next week... andan don't think the ADI-2 DAC on its own can power such headphones.

Thanks

Try Hi-power mode on the the ADI-2 and let us know how the Abyss-1266 sounds. (IMO the ADI-2 DAC's amp struggles with the low frequency impedance spike on Focal headphones - I hear more bass via the V281). Some pros and one con of the ADI-2 DAC to V281 pairing:

Pros:
  • Good synergy - the neutrality and detail of the ADI-2 DAC is what the V281 needs
  • Power of the V281 and the ability to go simple and use the ADI-2's built-in amp for easier to drive headphones and IEMs
  • Ability to connect via XLR or RCA and tweak ADI-2 Ref Line output level and V281 pre-gain to allow you to set a desired "normal" volume pot position on the V281
    • the volume pot on the ADI-2 can be used for minor sound level adjustments without audible impact on sound
    • you have the option of connecting a second device to the ADI-2 (all equipment should be connected to a common ground though)
  • DSP functions on the ADI-2 have no perceptible impact on sound quality
  • ADI-2 native DSD conversion to line out (DSD will be converted first to PCM if using the ADI-2's headphone jack)
Cons:
  • The V281 takes up a lot of desk space
  • The ADI-2 is wider than the V281 so you can't stack it on the V281
 
May 11, 2019 at 11:49 PM Post #1,273 of 4,643

Phoniac

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Try Hi-power mode on the the ADI-2 and let us know how the Abyss-1266 sounds. (IMO the ADI-2 DAC's amp struggles with the low frequency impedance spike on Focal headphones - I hear more bass via the V281).

You got it the wrong way round. The ADI has 0.1 Ohms output impedance and doesn't care about the Focal's impedance swing at all. If you hear more bass with the Violectric then it must have a higher output impedance to generate a slight bass boost. I doubt this is the case as it would require more than 30 Ohms output impedance to become audible.
 
May 12, 2019 at 6:58 PM Post #1,274 of 4,643

Anaz

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You got it the wrong way round. The ADI has 0.1 Ohms output impedance and doesn't care about the Focal's impedance swing at all. If you hear more bass with the Violectric then it must have a higher output impedance to generate a slight bass boost. I doubt this is the case as it would require more than 30 Ohms output impedance to become audible.

The V281 has an output impedance similar to that the ADI-2 (0.1 ohm SE and 0.2 ohm balanced) so its not that. I still think the ADI-2 on low power can't handle the power requirements of the Focal Clear and here's my reasoning:
  • The focal Clear's impedance spikes up to 322 ohms to 460 ohms (depending on which measurement you believe) at 50 Hz to 60 Hz
  • I haven't seen a measurement for the Clear's sensitivity across the frequency range, but if it drops to a plausible 100 dB at 50-60 Hz given the impedance spike, then the Clear needs 1.79 Vrms to play a 50-60Hz tone at 110 dB SPL
  • Low power mode on the ADI-2 is given as +7 dBu which is 1.73 Vrms - (1.73 V is also stated in the spec sheet)
  • Hi-Power mode is given as +22 dBu which is 9.75 Vrms and which should be more than sufficient
If my reasoning is flawed let me know. Thanks!

If it's useful to anyone, here's some data for Hi-Power mode (take the trendlines with a grain of salt):

RME ADI-2 DAC Hi-Power data table.png

Power Per Channel, Hi-Power.png

Current Per Channel, Hi-Power.png

Voltage Per Channel, Hi-Power.png
 
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May 13, 2019 at 12:19 AM Post #1,275 of 4,643

Phoniac

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You have both the ADI and the Violectric. Why are you not just trying/doing it? Connect the Focal's to the ADI in Low Power mode, put on some bass heavy music that includes 50 to 60 Hz, then cramp up the volume until your ears bleed - while looking at the level meter below the Analyser. If you can stand it while reaching full level / 0 dBFS on the meters then you need High Power mode. Else not. It's that simple to me...no need to calculate anything...
 

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